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7.1 © 2006 by Prentice Hall
6Chapter
Foundations of Business Foundations of Business Intelligence:Intelligence:
Databases and Information Databases and Information ManagementManagement
7.2 © 2006 by Prentice Hall
• Describe basic file organization concepts and the problems of managing data resources in a traditional file environment
• Describe how a database management system organizes information and compare the principal database models
• Apply important database design principles
Management Information SystemsManagement Information Systems
OBJECTIVES
7.3 © 2006 by Prentice Hall
File Organization Terms and Concepts File Organization Terms and Concepts
• Bit: Smallest unit of data; binary digit (0,1)
• Byte: Group of bits that represents a single character
• Field: Group of words or a complete number
• Record: Group of related fields
• File: Group of records of same type
ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Management Information SystemsManagement Information Systems
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• Database: Group of related files
• Entity: Person, place, thing, event about which information is maintained
• Attribute: Description of a particular entity
• Key field: Identifier field used to retrieve, update, sort a record
ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Management Information SystemsManagement Information Systems
File Organization Terms and Concepts (Continued)File Organization Terms and Concepts (Continued)
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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
The Data Hierarchy
Management Information SystemsManagement Information Systems
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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Entities and Attributes
Management Information SystemsManagement Information Systems
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Problems with the Traditional File Environment
Data Redundancy and Inconsistency:
• Data redundancy: The presence of duplicate data in multiple data files so that the same data are stored in more than one place or location
• Data inconsistency: The same attribute may have different values.
ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Management Information SystemsManagement Information Systems
7.8 © 2006 by Prentice Hall
• The coupling of data stored in files and the specific programs required to update and maintain those files such that changes in programs require changes to the data
Lack of flexibility:
• A traditional file system can deliver routine scheduled reports after extensive programming efforts, but it cannot deliver ad-hoc reports or respond to unanticipated information requirements in a timely fashion.
ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Management Information SystemsManagement Information SystemsChapter 7 Chapter 7 Managing Data ResourcesManaging Data Resources
Program-data dependence:
Problems with the Traditional File Environment (Continued)
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• Because there is little control or management of data, management will have no knowledge of who is accessing or even making changes to the organization’s data.
Lack of data sharing and availability:
• Information cannot flow freely across different functional areas or different parts of the organization. Users find different values of the same piece of information in two different systems, and hence they may not use these systems because they cannot trust the accuracy of the data.
ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Management Information SystemsManagement Information Systems
Poor security:Problems with the Traditional File Environment (Continued)
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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
Traditional File Processing
Management Information SystemsManagement Information Systems
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Database Management System (DBMS)
• Software for creating and maintaining databases
• Permits firms to rationally manage data for the entire firm
• Acts as interface between application programs and physical data files
• Separates logical and design views of data
• Solves many problems of the traditional data file approach
THE DATABASE APPROACH TO DATA MANAGEMENT
Management Information SystemsManagement Information Systems
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The Contemporary Database Environment
THE DATABASE APPROACH TO DATA MANAGEMENT
Management Information SystemsManagement Information Systems
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Components of DBMS:
• Data definition language: Specifies content and structure of database and defines each data element
• Data manipulation language: Used to process data in a database
• Data dictionary: Stores definitions of data elements and data characteristics two types : passive and active
THE DATABASE APPROACH TO DATA MANAGEMENT
Management Information SystemsManagement Information Systems
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Sample Data Dictionary Report
THE DATABASE APPROACH TO DATA MANAGEMENT
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Types of Databases:
• Relational DBMS
• Hierarchical and network DBMS
• Object-oriented databases
THE DATABASE APPROACH TO DATA MANAGEMENT
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Relational DBMS:
• Represents data as two-dimensional tables called relations
• Relates data across tables based on common data element
• Examples: DB2, Oracle, MS SQL Server
THE DATABASE APPROACH TO DATA MANAGEMENT
Management Information SystemsManagement Information Systems
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The Relational Data Model
THE DATABASE APPROACH TO DATA MANAGEMENT
Management Information SystemsManagement Information Systems
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Three Basic Operations in a Relational Database:
• Select: Creates subset of rows that meet specific criteria
• Join: Combines relational tables to provide users with information
• Project: Enables users to create new tables containing only relevant information
THE DATABASE APPROACH TO DATA MANAGEMENT
Management Information SystemsManagement Information Systems
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The Three Basic Operations of a Relational DBMS
THE DATABASE APPROACH TO DATA MANAGEMENT
Management Information SystemsManagement Information Systems
7.20 © 2006 by Prentice Hall
Hierarchical and Network DBMS Hierarchical and Network DBMS
• Organizes data in a tree-like structure
• Supports one-to-many parent-child relationships
• Prevalent in large legacy systems
THE DATABASE APPROACH TO DATA MANAGEMENT
Hierarchical DBMS:
Management Information SystemsManagement Information Systems
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A Hierarchical Database for a Human Resources System
THE DATABASE APPROACH TO DATA MANAGEMENT
Management Information SystemsManagement Information Systems
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Hierarchical and Network DBMS Hierarchical and Network DBMS
• Depicts data logically as many-to-many relationships
THE DATABASE APPROACH TO DATA MANAGEMENT
Network DBMS:
Management Information SystemsManagement Information Systems
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The Network Data Model
Management Information SystemsManagement Information Systems
THE DATABASE APPROACH TO DATA MANAGEMENT
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Hierarchical and Network DBMS Hierarchical and Network DBMS
• Outdated
• Less flexible compared to RDBMS
• Lack support for ad-hoc and English language-like queries
• All paths for accessing data must be specified in advance.
Disadvantages:
Management Information SystemsManagement Information Systems
THE DATABASE APPROACH TO DATA MANAGEMENT
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• Object-oriented DBMS: Stores data and procedures as objects that can be retrieved and shared automatically
• Handling graphics-based or multimedia applications
• slower than RDBMS for processing large transactions
• Object-relational DBMS: Provides capabilities of both object-oriented and relational DBMS
Object-Oriented Databases:
Management Information SystemsManagement Information Systems
THE DATABASE APPROACH TO DATA MANAGEMENT
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• Conceptual design: Abstract model of database from a business perspective
• Physical design: Detailed description of business information needs .How the database is actually arranged on direct-access storage devices
CREATING A DATABASE ENVIRONMENT
Designing Databases:
Management Information SystemsManagement Information Systems
7.27 © 2006 by Prentice Hall
• Entity-relationship diagram: Methodology for documenting databases illustrating relationships between database entities
• Normalization: Process of creating small stable data structures from complex groups of data
CREATING A DATABASE ENVIRONMENT
Management Information SystemsManagement Information Systems
Designing Databases: (Continued)
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An Unnormalized Relation for ORDER
CREATING A DATABASE ENVIRONMENT
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Normalized Tables Created from ORDER
CREATING A DATABASE ENVIRONMENT
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CREATING A DATABASE ENVIRONMENT
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An Entity-Relationship Diagram
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An Entity-Relationship Diagram
CREATING A DATABASE ENVIRONMENT
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how the data are to be distributed
Two ways,
1. Centralized database
2. Distributed database
CREATING A DATABASE ENVIRONMENT
Distributing DatabasesDistributing Databases
Management Information SystemsManagement Information Systems
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Centralized database:
• Used by single central processor or multiple processors in client/server network
• There are advantages and disadvantages to having all corporate data in one location.
• Security is higher in central environments, risks lower.
CREATING A DATABASE ENVIRONMENT
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• Databases can be decentralized either by
partitioning or by replicating
• Partitioned database: Database is divided into
segments or regions. For example, a customer
database can be divided into Eastern customers
and Western customers, and two separate
databases maintained in the two regions.
CREATING A DATABASE ENVIRONMENT
Distributed database:
Management Information SystemsManagement Information Systems
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• Duplicated database: The database is completely duplicated at two or more locations. The separate databases are synchronized in off hours on a batch basis.
• Regardless of which method is chosen, data administrators and business managers need to understand how the data in different databases will be coordinated and how business processes might be effected by the decentralization.
CREATING A DATABASE ENVIRONMENT
Management Information SystemsManagement Information SystemsChapter 7 Chapter 7 Managing Data ResourcesManaging Data Resources
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Distributed Databases
CREATING A DATABASE ENVIRONMENT
Management Information SystemsManagement Information Systems
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Distributed DatabasesCREATING A DATABASE ENVIRONMENT
Management Information SystemsManagement Information Systems
Advantages
-Reduces the vulnerability of a single, massive central database
Disadvantages
-However it depends on high-quality telecommunications which
themselves are vulnerable.
-Local database can sometimes depart.
-Security problem by widely distributing access to sensitive data
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• The quality of decision making in a firm is directly related to the quality of data in its databases.
• Data Quality Audit: Structured survey of the accuracy and level of completeness of the data in an information system
• Data Cleansing: Consists of activities for detecting and correcting data in a database or file that are incorrect, incomplete, improperly formatted, or redundant
CREATING A DATABASE ENVIRONMENT
Management Information SystemsManagement Information Systems
Ensuring Data Quality:
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Online Analytical Processing (OLAP):
• Multidimensional data analysis – Slicing and Dicing
• Supports manipulation and analysis of large volumes of data from multiple dimensions/perspectives
• Multidimensional analysis enables users to view the same data in different ways using multiple dimensions
• Each aspect of information- products,cost,region or time period represents a different dimensions
DATABASE TRENDS
Multidimensional Data AnalysisMultidimensional Data Analysis
Management Information SystemsManagement Information Systems
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Multidimensional Data Model
DATABASE TRENDS
Management Information SystemsManagement Information Systems
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DATABASE TRENDS
Management Information SystemsManagement Information Systems
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DATABASE TRENDS
Management Information SystemsManagement Information Systems
Slicing
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DATABASE TRENDS
Management Information SystemsManagement Information Systems
Dicing
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Data warehouse:
• Supports reporting and query tools
• Stores current and historical data
• Consolidates data for management analysis and decision making
• Data are standardised and consolidated in a single place
DATABASE TRENDS
Data Warehousing and Data Mining Data Warehousing and Data Mining
Management Information SystemsManagement Information Systems
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Data warehouse:
• The data originate in many core operational systems & external sources including web site transactions.
• The data from these diverse applications are copied into the data warehouse database often as needed- hourly,daily,weekly
• Data are available to everyone but can not be altered
DATABASE TRENDS
Data Warehousing and Data Mining Data Warehousing and Data Mining
Management Information SystemsManagement Information Systems
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Components of a Data Warehouse
DATABASE TRENDS
Management Information SystemsManagement Information Systems
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Data mart:
• Subset of data warehouse
• Contains summarized or highly focused portion of data for a specified function or group of users
• Typically focus on a single subject
• Eg:A company might develop a marketing & sales data marts to deal with customer information
• However,complexity,cost & management problems will arise if an organization creates too many data marts
DATABASE TRENDS
Management Information SystemsManagement Information Systems
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• Tools for analysing large pools of data
• There are many mining applications
• Uses variety of techniques to find hidden patterns & relationship in large pools of data & infer rules from them that can be used to predict future behaviour & guide decision making.
• “Data image” - Data mining technique can combine information from many diverse sources to create a detailed Data image.
DATABASE TRENDS
Data mining:
Management Information SystemsManagement Information Systems
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Benefits of Data Warehouses:
• Improved and easy accessibility to information
• Ability to model and remodel the data
• Enable decision makers to access data without affecting the performance of the underlying operational system
• It can be accessed using web technology also.
DATABASE TRENDS
Management Information SystemsManagement Information Systems
7.50 © 2006 by Prentice Hall
The Web and Hypermedia database:
• Organizes data as network of nodes
• Links nodes in pattern specified by user
• Supports text, graphic, sound, video, and executable programs
DATABASE TRENDS
Databases and the Web Databases and the Web
Management Information SystemsManagement Information Systems
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A Hypermedia Database
DATABASE TRENDS
Management Information SystemsManagement Information Systems
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Database server:
• Computer in a client/server environment runs a
DBMS to process SQL statements and perform
database management tasks.
Application server:
• Software handling all application operations
DATABASE TRENDS
Management Information SystemsManagement Information Systems
Databases and the Web
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Advantage in using the web to access an
organization's internal database
Web browser software is extremely easy to
use. Requires less training for the user.
The web interface requires no changes to the
internal database
DATABASE TRENDS
Management Information SystemsManagement Information Systems
Databases and the Web
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Linking Internal Databases to the Web
DATABASE TRENDS
Management Information SystemsManagement Information Systems
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MANAGEMENT OPPORTUNITIES, CHALLENGES, AND SOLUTIONS
Management Information SystemsManagement Information Systems
Management Challenges:
• Need cooperation in developing corporate-wide data administration
• Cost/benefit considerations
Bringing about significant change in the database environment of a firm can be very expensive and time consuming.